How can I send email from SMTP and PHP ?

Here's a third party article that discusses using PHP and SMTP to send email: http://email.about.com/od/emailprogrammingtips/qt/et073006.htm.

How to authorize a remote IP to relay throught Exim:

1. Create a file with your host IP or IPs
2. Name it something like /etc/privaterelay.
3. In /etc/exim.conf, change the first line below to the second.
   • hostlist relay_hosts = lsearch;/etc/relayhosts : \
     localhost
   • hostlist relay_hosts = lsearch;/etc/relayhosts : \
     localhost : lsearch;/etc/privaterelay